Test apparatus, water stop life estimation program, and water stop performance evaluation method

Abstract

The object of the present invention is to solve the problems of the prior art, namely, to provide a test apparatus that can evaluate the water-stopping performance of a water-stopping material accurately and at low cost compared to the prior art, as well as a water-stopping life estimation program and a water-stopping performance evaluation method that can estimate the water-stopping life of a water-stopping material. [Solution] The test apparatus of the present invention is a device that can evaluate the water-stopping performance of a test specimen, and comprises an upper compression plate, a lower compression plate, a joining means, and a pumping means. The upper compression plate has water injection holes that penetrate in the plate thickness direction. An annular test specimen is placed between the upper and lower compression plates in a plan view, and the test specimen is tightened by the joining means until it reaches the planned compression ratio. When the pumping means pumps water into the inside of the test specimen through the water injection holes, the water-stopping performance can be evaluated by whether or not there is water leakage from the test specimen.

Description

Technical Field

[0001] The present invention is a technology for evaluating the water-stopping performance of a water-stopping material. More specifically, it relates to a test device capable of evaluating the water-stopping performance by applying water pressure to a test specimen, a water-stopping life estimation program capable of estimating the life of the water-stopping material, and a water-stopping performance evaluation method for evaluating the water-stopping performance using the test device.

Background Art

[0002] In facilities that do not allow water intrusion from the outside, a water-stopping structure is provided at parts where water is likely to intrude. For example, it is common to install a water-stopping packing on the opening and closing door of a water-tight room, and a water-stopping packing may also be provided on the casing of electrical equipment. In addition, a water-stopping structure is often provided at the joint part of a water supply pipe to prevent leakage from the inside of the pipe, or a water-stopping structure is provided at the joint part of a concrete retaining wall to prevent groundwater from flowing out from the ground.

[0003] As the water-stopping packing as a water-stopping structure, "rubber packing" mainly made of rubber (especially synthetic rubber) is the mainstream. Rubber is known to undergo aging deterioration, and naturally, when the rubber deteriorates, it affects the water-stopping performance of the rubber packing. And when the water-stopping performance of the rubber packing deteriorates, it is necessary to replace or repair the rubber packing.

[0004] Regarding the replacement and repair of rubber packings, various techniques have been proposed so far. For example, in Patent Document 1, as a repair method when a recess occurs on the front side of the rubber packing, a technique of pushing out the front side of the rubber packing by installing a "patch" on the back side of the rubber packing has been proposed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The technology disclosed in Patent Document 1 is a method for repairing rubber gaskets, essentially a technology to extend their lifespan. However, since rubber gaskets will eventually lose their water-sealing performance and require replacement, repairing them is only a temporary solution. Ideally, rubber gaskets should be replaced when their water-sealing performance is lost, but it is not practical to constantly monitor the condition of rubber gaskets to determine that timing. Therefore, it is conceivable to predict the lifespan of rubber gaskets in advance and replace them according to that lifespan.

[0007] When evaluating the lifespan of vulcanized rubber and thermoplastic rubber, the method according to the Japanese Industrial Standard (JIS K6262) is commonly used. This method involves placing a test specimen (rubber) in a constant temperature chamber for a certain period to accelerate thermal degradation, and then measuring the compression set. This test is repeated under different ambient temperatures, and the lifespan is defined as approximately 80% of the compression set. An "Arrhenius equation" is then created using the combination of ambient temperature and lifespan (a kind of coordinate system). By inputting the actual ambient temperature into this Arrhenius equation, the lifespan of the rubber gasket to be used can be predicted.

[0008] Originally, the above method is a test to understand the degree of rubber "deterioration" (hereinafter referred to as the "deterioration test" for convenience) and does not directly evaluate the water-sealing performance of the rubber. In fact, when the inventor of the present invention performed this deterioration test and determined the lifespan of the rubber gasket's water-sealing function (hereinafter simply referred to as the "water-sealing lifespan"), an extremely short water-sealing lifespan was obtained compared to the actual water-sealing lifespan. The cause of this contradiction is thought to be the characteristics of the rubber gasket. In particular, rubber gaskets used for water sealing are sponge-like, so they absorb water that has entered from the outside and expand, and the water-sealing performance is ensured by the repulsive force caused by this expansion that prevents water from entering. In other words, even if the rubber has deteriorated, it can still perform as a water-sealing structure if it expands, and therefore the water-sealing lifespan of the rubber gasket cannot be accurately evaluated by the deterioration test.

[0009] To evaluate the water-sealing performance of rubber gaskets, actual equipment testing is sometimes conducted instead of wear tests. That is, water-sealing tests are performed using a device incorporating an actual watertight door to evaluate the water-sealing performance of the rubber gasket. However, such tests using actual equipment require the preparation of large-scale equipment, the use of large amounts of water, and the securing of a large installation space, so the tests are quite costly.

[0010] The object of the present invention is to solve the problems of the prior art, namely, to provide a test apparatus that can evaluate the water-stopping performance of a water-stopping material accurately and at low cost compared to the prior art, a water-stopping life estimation program for estimating the water-stopping life of a water-stopping material, and a water-stopping performance evaluation method for evaluating the water-stopping performance of a water-stopping material. [Means for solving the problem]

[0011] The present invention focuses on evaluating the water-stopping performance of a compressed test specimen by applying water pressure, and is based on a completely new idea.

[0012] The test apparatus of the present invention is capable of evaluating the water-stopping performance of a test specimen, and comprises an upper compression plate, a lower compression plate, a joining means, and a pumping means. The upper and lower compression plates are plate-shaped members, and the upper compression plate has a water injection hole that penetrates in the direction of the plate thickness. The joining means is a means for joining the upper and lower compression plates, and the pumping means is a means for pumping water through the water injection hole. When an annular test specimen is placed between the upper and lower compression plates in a plan view, the upper and lower compression plates are tightened by the joining means until the test specimen reaches the planned compression ratio, and water is pumped into the inside of the test specimen through the water injection hole by the pumping means, the water-stopping performance can be evaluated by whether or not there is water leakage from the test specimen.

[0013] The test apparatus of the present invention may further be equipped with a pressure measuring means. This pressure measuring means is a means for measuring the pressure when the pumping means pumps water. In this case, when the pumping means pumps water into the inside of the test specimen through the water injection hole, the water-stopping performance can be evaluated based on the pressure measured by the pressure measuring means.

[0014] The test apparatus of the present invention may further include a spacer. In this case, the test specimen is compressed, i.e., fastened by a joining means, with a spacer placed between the upper compression plate and the lower compression plate.

[0015] The test apparatus of the present invention may further include a heating means. This heating means is a means for housing and heating a test specimen placed between an upper compression plate and a lower compression plate. The test specimen housed in the heating means is visible from the outside. In this case, a water supply pipe that penetrates a part of the heating means connects the water injection port to a pressure supply means located outside the heating means.

[0016] The water-stopping life estimation program of the present invention is equipped with functions to have a computer perform data input processing, estimation formula setting processing, and period estimation processing. In the data input processing, multiple test data are received; in the estimation formula setting processing, a "water-stopping life estimation formula" is set using the input test data; and in the period estimation processing, the "water-stopping period (the period until the test specimen becomes unable to stop water)" is output based on the input ambient temperature and the water-stopping life estimation formula. The water-stopping life estimation formula is a regression equation based on multiple test data, and is a function in which ambient temperature is the explanatory variable and water-stopping period is the dependent variable. The test data includes the water-stopping period (the period from the start of the test until it is evaluated that water-stopping is no longer possible) at each ambient temperature, obtained by repeatedly performing a test in which water is pumped using the test apparatus of the present invention on each test specimen that has been heated and held at multiple planned ambient temperatures.

[0017] The water-sealing performance evaluation method of the present invention is a method for evaluating the water-sealing performance of a test specimen using the test apparatus of the present invention, and comprises a test specimen placement step, a heating and holding step, and a testing step. In the test specimen placement step, the test specimen and spacer are placed between the upper and lower compression plates, and the upper and lower compression plates are tightened by a joining means until the distance between the upper and lower compression plates becomes the thickness of the spacer. In the heating and holding step, the test specimen placed between the upper and lower compression plates is heated and held at a planned ambient temperature, and in the testing step, water is pumped into the inside of the test specimen through a water injection hole by a pumping means. By performing this series of steps, the water-sealing performance of the test specimen at ambient temperature can be evaluated.

[0018] The water-stopping performance evaluation method of the present invention may further include a water-stopping period confirmation step and an estimation formula setting step. In the water-stopping period confirmation step, the test process is repeated until the test specimen is evaluated as unable to stop water, and the water-stopping period from the start of the test at ambient temperature until it is evaluated as unable to stop water is confirmed. In the estimation formula setting step, the water-stopping period confirmation step is performed on test specimens heated and held at multiple different ambient temperatures, thereby obtaining multiple test data consisting of ambient temperature and water-stopping period, and a water-stopping life estimation formula is set using these test data. The water-stopping life estimation formula is a regression equation based on multiple test data, and is a function with ambient temperature as the explanatory variable and water-stopping period as the dependent variable.

[0019] The water-stopping performance evaluation method of the present invention may further include a planned compression ratio setting step. In this planned compression ratio setting step, the planned compression ratio is set using the test apparatus of the present invention, and more specifically, after tightening the test specimen, water is pumped into the inside of the test specimen at a hydrostatic pressure corresponding to the required immersion depth. Then, the planned compression ratio setting step is repeated while increasing the compression ratio of the test specimen, and the compression ratio at which the water-stopping performance of the test specimen is confirmed is set as the planned compression ratio. [Effects of the Invention]

[0020] The test apparatus, water-stopping life estimation program, and water-stopping performance evaluation method of the present invention have the following effects. (1) The water-sealing performance and lifespan of water-sealing materials used in watertight doors, electrical equipment, etc. can be evaluated directly and easily. (2) The compressibility and water-stopping performance of the water-stopping material necessary to ensure the target water-stopping performance can be determined using relatively simple equipment. [Brief explanation of the drawing]

[0021] [Figure 1] A schematic block diagram showing the test apparatus of the present invention. [Figure 2] A plan view from above of the lower compression plate on which the annular test specimens are arranged. [Figure 3](a) is a front view schematically showing a test specimen before being compressed in a compression tester, and (b) is a front view schematically showing the compressed test specimen. [Figure 4] A perspective view schematically showing a heating means through which a water supply pipe is inserted. [Figure 5] A flowchart showing a procedure for evaluating the water-stopping performance of a test specimen using the test apparatus of the present invention. [Figure 6] A flowchart showing a procedure for obtaining a plurality of test data using the test apparatus of the present invention in order to estimate the water-stopping life of a water-stopping material by the water-stopping life estimation program of the present invention. [Figure 7] A flowchart showing the main processes executed by the water-stopping life estimation program of the present invention. [Figure 8] (a) is a graph showing a water-stopping life estimation formula set from test results using a test specimen of hard rubber, and (b) is a graph showing a water-stopping life estimation formula set from test results using a test specimen of soft rubber. [Figure 9] A flowchart showing the flow of the main steps of the water-stopping performance evaluation method of the present invention.

Embodiments for Carrying Out the Invention

[0022] An example of an embodiment of the test apparatus, the water-stopping life estimation program, and the water-stopping performance evaluation method of the present invention will be described based on the drawings.

[0023] 1. Test Apparatus First, the test apparatus of the present invention will be described in detail with reference to the drawings. The water-stopping life estimation program of the present invention estimates the water-stopping life of a water-stopping material based on test data obtained using the test apparatus of the present invention, and the water-stopping performance evaluation method of the present invention is a method for evaluating the water-stopping performance of a water-stopping material using the test apparatus of the present invention. Therefore, first, the test apparatus of the present invention will be described, and then the water-stopping life estimation program and the water-stopping performance evaluation method of the present invention will be described in detail.

[0024] Figure 1 is a schematic block diagram showing the test apparatus 100 of the present invention. As shown in this figure, the test apparatus 100 of the present invention is composed of an upper compression plate 110, a lower compression plate 120, a joining means 140, and a pumping means 150, and may also be composed of a spacer 130, a pressure measuring means 160, a water supply pipe WP, a heating means 170, etc. For convenience, the upper compression plate 110, the lower compression plate 120, and the joining means 140 will be collectively referred to as the "compression tester."

[0025] The test apparatus 100 evaluates the performance of the test specimen TP as a waterproofing material by pressurizing water into the compressed test specimen TP. The test method for evaluating the waterproofing performance of the test specimen TP using the test apparatus 100 is generally carried out in the following steps. First, a spacer 130 and an annular (ring-shaped) test specimen TP are placed between the upper compression plate 110 and the lower compression plate 120, and the upper compression plate 110 and the lower compression plate 120 are tightened with a joining means 140 to compress the test specimen TP until it is the same thickness as the spacer 130. Next, the compression tester with the test specimen TP set in it is placed in a heating means 170 such as an oven, adjusted to a predetermined ambient temperature, and held for a certain period of time to accelerate the thermal degradation of the test specimen TP. After a certain period of time has elapsed, the compression tester is removed from the heating means 170, the water supply pipe WP is connected to the water injection hole 110H of the upper compression plate 110, and water is pressurized into the test specimen TP in the compression tester by a pressurizing means 150 such as a pump. In this case, since the water is supplied to the inside of the annular test specimen TP, if the water-sealing performance of the test specimen TP is effective, no water will leak to the outside. However, if the water-sealing performance has deteriorated to a considerable extent, water will leak to the outside, and this allows us to evaluate the water-sealing performance.

[0026] The upper compression plate 110 and the lower compression plate 120 are each plate-shaped with a certain thickness (about several centimeters), and as described above, a water injection hole 110H is formed in the upper compression plate 110. However, the water injection hole 110H is formed in a position where it is projected onto the inside of the annular test specimen TP, that is, as shown by the dashed line in Figure 2, so that water is supplied to the inside of the test specimen TP.

[0027] Figure 2 is a plan view from above of the lower compression plate 120 on which the annular test specimen TP is placed. As shown in this figure, the lower compression plate 120 is provided with several (four in the figure) through holes (hereinafter referred to as "lower bolt holes 120H"), and bolts 141 that constitute the joining means 140 are inserted through these lower bolt holes 120H.

[0028] The spacer 130 is used to regulate the distance between the upper compression plate 110 and the lower compression plate 120. The spacer 130 is positioned to be equal in thickness to the planned thickness (hereinafter referred to as "planned thickness") so that the test specimen TP is compressed to the planned thickness. The spacer 130 can be detachably fixed to the lower compression plate 120 (or upper compression plate 110), or it can be simply placed as an independent component. Alternatively, the test specimen TP can be compressed while measuring until it reaches the planned thickness, in which case the spacer 130 can be omitted. Figure 2 shows an example where four lower bolt holes 120H and four spacers 130 are placed, but of course, the number can be set arbitrarily, and it is preferable to place multiple lower bolt holes 120H and spacers 130 on the outside of the test specimen TP so that they are symmetrical along a line or point. In addition, although the test specimen TP shown in Figure 2 is generally rectangular in shape, various shapes of test specimen TP can be used, including circular (donut-shaped) specimens, as long as they are annular.

[0029] When using spacers 130, only one layer of spacers 130 with the planned thickness can be installed. For example, in Figure 2, spacers 130 are placed in four locations that are different from the lower bolt holes 120H (i.e., bolts 141) and are on the outside of the test specimen TP, with only one layer of spacers 130 having the planned thickness placed in each location. Alternatively, the planned thickness can be secured by stacking multiple layers of spacers 130 at each location (four locations in the example of Figure 2). For example, the planned thickness can be secured by inserting multiple washers onto bolt 141. In other words, washers are inserted onto bolt 141 so that the planned thickness is obtained by multiplying the thickness of the washers by the number of washers (number of layers), and then the test specimen TP is compressed.

[0030] To evaluate the water-stopping performance of the test specimen TP using the test apparatus 100 of the present invention, as described above, the test specimen TP is compressed to the planned thickness, and then water is pumped into the inside of the annular test specimen TP. Various conventional techniques can be used to compress the test specimen TP, for example, a joining means 140 consisting of a bolt 141 and a nut 142 can be used as shown in Figure 3. Figure 3 is a schematic diagram of a compression tester equipped with a joining means 140 consisting of a bolt 141 and a nut 142, where (a) is a front view showing the state before the test specimen TP is compressed, and (b) is a front view showing the state after the test specimen TP has been compressed.

[0031] The following describes the procedure for compressing the test specimen TP using the joining means 140 shown in Figure 3. First, the bolt 141 is inserted from below into the lower bolt hole 120H of the lower compression plate 120, and the spacer 130 and the test specimen TP are placed on the lower compression plate 120. Next, the bolt 141 is inserted into the through hole provided in the upper compression plate 110, and the upper compression plate 110 is placed on the upper surface of the test specimen TP, and the nut 142 is screwed onto the portion of the bolt 141 that protrudes upward from the upper compression plate 110. Then, the nut 142 is tightened until the distance between the upper compression plate 110 and the lower compression plate 120 becomes the thickness of the spacer 130, in other words, until the upper compression plate 110 and the lower compression plate 120 each come into contact with the spacer 130, thereby compressing the test specimen TP to the planned thickness (i.e., the thickness of the spacer 130). If the spacer 130 is omitted, the test specimen TP is compressed until the planned thickness is reached while measuring its thickness.

[0032] The test specimen TP, compressed to the planned thickness, is placed in the heating means 170 along with the compression tester and held at a predetermined ambient temperature for a certain period of time. After that, a "pressure test" is performed by connecting the water supply pipe WP to the water injection hole 110H and pressurizing water from the pressure feeding means 150 to the test specimen TP. In this case, if a normal oven or the like is used as the heating means 170, it is necessary to remove the compression tester from the heating means 170 in order to perform the pressure test, and after the pressure test, the compression tester must be placed back into the heating means 170.

[0033] Therefore, it is preferable to use a heating means 170 that allows the compression test to be performed without removing the compression tester from the heating means 170, that is, a heating means 170 that allows the compression test to be performed while the compression tester remains housed within the heating means 170. For example, the heating means 170 shown in Figure 4 is provided with a small hole (hereinafter referred to as the "water supply pipe hole") that penetrates a part of it (the ceiling surface in the figure), and a water supply pipe WP can be inserted through this water supply pipe hole. As a result, by placing the compression tester with the test specimen TP set inside the heating means 170, passing the water supply pipe WP through the water supply pipe hole, and further connecting the water supply pipe WP to the water injection hole 110H, it is possible to perform the compression test while the compression tester remains housed within the heating means 170. In this case, it is preferable to make the opening and closing door of the heating means 170 out of a transparent material (for example, glass) so that the compression tester can be visually checked even when the opening and closing door is closed.

[0034] If no water leakage is detected from the test specimen TP as a result of the pumping test, its water-stopping performance is evaluated as effective. On the other hand, if water leakage is detected from the test specimen TP, its water-stopping performance is evaluated as insufficient (hereinafter referred to as "water-stopping failure"). Thus, the water-stopping performance of the test specimen TP can be evaluated by visually checking for water leakage from the test specimen TP, or by using a pressure measuring means 160 (Figure 1) that measures the pressure (hereinafter referred to as "water supply pressure") when the pumping means 150 is supplying water. If the water-stopping performance of the test specimen TP is effective, the pumping means 150 will continue to supply water at a predetermined water supply pressure. However, if the water-stopping performance has deteriorated to a considerable extent, the water will be supplied at a water supply pressure lower than the predetermined water supply pressure. Therefore, when the measured value of the pressure measuring means 160 falls below the initially set water supply pressure, or more specifically, when the measured value of the pressure measuring means 160 falls below a predetermined threshold (hereinafter referred to as the "pressure threshold"), the test specimen TP can be evaluated as being unable to stop water.

[0035] Figure 5 is a flowchart showing an example of using the test apparatus 100 of the present invention. The procedure for evaluating the water-stopping performance of the test specimen TP using the test apparatus 100 will be described below with reference to this figure. First, various conditions when actually using the water-stopping material should be confirmed, in particular the ambient temperature of the place of use, the pressure acting on the water-stopping material at the place of use (hereinafter referred to as "ambient pressure"), and the planned compressibility of the water-stopping material (hereinafter referred to as "planned compressibility") (Step 201 in Figure 5). The planned compressibility can be set to a predetermined value, or it can be set as "a compressibility that matches the hydrostatic pressure required as the inundation depth, i.e., the water-stopping performance." When setting the planned compressibility according to the required performance, it is advisable to perform a pumping test using the test apparatus 100 while gradually changing the compressibility of the test specimen TP. The procedure will be described below. First, a pumping test is performed on the test specimen TP that has been compressed to a predetermined compressibility. If a water leak is detected or the measurement value of the pressure measuring means 160 falls below the pressure threshold (hereinafter collectively referred to as "water-stopping performance not being confirmed"), the test specimen TP is compressed to an even higher compression ratio (i.e., to become thinner) and a pumping test is performed. This series of procedures is repeated until no more water leaks are detected or the measurement value of the pressure measuring means 160 exceeds the pressure threshold (hereinafter collectively referred to as "water-stopping performance being confirmed"), and the limiting compression ratio is determined and that limiting value is set as the planned compression ratio.

[0036] Once all conditions, including the planned compression ratio, are determined, the test specimen TP is placed in the compression tester (Step 202 in Figure 5), the planned compression ratio is confirmed (Step 203 in Figure 5), and the test specimen TP is compressed until it reaches that planned compression ratio. To do this, the "compressed thickness Ta" is calculated using the following equation, which consists of the "planned compression ratio Pc" and the "natural thickness Tu," and the test specimen TP is compressed using a spacer 130 having this compressed thickness Ta (or while measuring the thickness of the test specimen TP). Here, the natural thickness Tu is the thickness of the test specimen TP in its natural state, and the compressed thickness Ta is the thickness of the compressed test specimen TP (in this case, the planned thickness). Compression thickness Ta = Natural thickness Tu × (1 - Planned compression ratio Pc)

[0037] After compressing the test specimen TP to the planned thickness, the test specimen TP is placed in the heating means 170 along with the compression tester, and the heating means 170 is adjusted to the ambient temperature of the place of use (Step 204 in Figure 5). The test specimen TP is then held in this state for a certain period of time (Step 205 in Figure 5). Subsequently, a "pressure feeding test" is performed by connecting the water supply pipe WP to the water injection hole 110H and feeding water from the pressure feeding means 150 to the test specimen TP (Step 206 in Figure 5). If the water-stopping performance is confirmed (no water leakage is detected, or the measurement value of the pressure measuring means 160 exceeds the pressure threshold), the water-stopping material made of the test specimen TP is evaluated as being able to sufficiently perform water-stopping performance in the actual place of use. On the other hand, if the water-stopping performance is not confirmed (water leakage is detected, or the measurement value of the pressure measuring means 160 falls below the pressure threshold), the water-stopping material made of the test specimen TP is evaluated as not being able to perform water-stopping performance in the actual place of use.

[0038] 2. Water stop life estimation program Next, the water-stopping life estimation program of the present invention will be explained in detail with reference to the diagram. The water-stopping life estimation program of the present invention estimates the water-stopping life of the water-stopping material based on the test data obtained using the test apparatus 100 described above. Therefore, explanations that overlap with those described for the test apparatus 100 will be avoided, and the explanation will mainly focus on the content specific to the water-stopping life estimation program of the present invention. In other words, content not described here is the same as that described in "1. Test Apparatus".

[0039] As described above, the water-stopping life estimation program of the present invention estimates the water-stopping life of a water-stopping material based on multiple test data obtained using the test device 100. Therefore, the procedure for obtaining multiple test data using the test device 100 will first be explained with reference to Figure 6.

[0040] First, various plans for conducting the test are formulated, including the setting of various conditions for conducting the test (hereinafter simply referred to as "test conditions") (Step 301 in Figure 6). Here, the test conditions include the planned compressibility of the test specimen TP, the water supply pressure when the pumping means 150 supplies water (hereinafter referred to as "planned water supply pressure"), and the ambient temperature when the test specimen TP is held by the heating means 170 (hereinafter referred to as "planned ambient temperature"). Of these, the planned compressibility of the test specimen TP can be set to a predetermined value as described above, or it can be set by conducting a pumping test using the test apparatus 100 while gradually changing (increasing) the compressibility of the test specimen TP. It is recommended to set at least two types of test conditions, such as the planned compressibility, planned water supply pressure, and planned ambient temperature, and to repeatedly conduct tests under each set test condition. It is also possible to prepare multiple types of test specimens TP made of different materials and repeatedly conduct tests on each test specimen TP.

[0041] Once the test conditions are set, the test specimen TP is placed in the compression tester (Step 302 in Figure 6), the planned compression ratio is confirmed (Step 303 in Figure 6), and the test specimen TP is compressed until it reaches the planned thickness calculated based on that planned compression ratio. Once the test specimen TP is compressed to the planned thickness, the test specimen TP is placed in the heating means 170 along with the compression tester, and the heating means 170 is adjusted to the planned ambient temperature (Step 304 in Figure 6), and the test specimen TP is held in that state for a certain period of time (Step 305 in Figure 6). After that, a "pressure feeding test" is performed in which the water supply pipe WP is connected to the water injection hole 110H and water is pressure-fed to the test specimen TP from the pressure feeding means 150 (Step 306 in Figure 6).

[0042] If the water-stopping performance is confirmed as a result of the pumping test (Yes in Step 307 of Figure 6), the test specimen TP is held again for a certain period of time, and then the pumping test is performed again. On the other hand, if the water-stopping performance is not confirmed (No in Step 307 of Figure 6), the period from when the test started until when it was evaluated (hereinafter referred to as the "water-stopping period") is recorded in relation to the planned ambient temperature (Step 308 of Figure 6). In other words, it is recorded as a combination of the planned ambient temperature and the water-stopping period (hereinafter referred to as the "temperature period data").

[0043] In this case, if the test is conducted at only some of the set planned ambient temperatures (No. in Step 309 of Figure 6), the heating means 170 is adjusted to a different planned ambient temperature (Step 304), and the series of steps from maintaining that planned ambient temperature (Step 305) to recording the water shut-off period (Step 308) is repeated. On the other hand, if the test is conducted at all of the set planned ambient temperatures (Yes in Step 309 of Figure 6), multiple temperature period data (planned ambient temperature, water shut-off period) are obtained under the same test conditions.

[0044] When testing is performed using only some of the set test conditions (No. in Step 310 of Figure 6), the test conditions (planned compression ratio, planned water supply pressure, and type of test specimen TP) are changed, and the series of steps from setting up the test specimen (Step 303) to recording the water shutoff period (Step 308) is repeated. On the other hand, when testing is performed using all of the set test conditions (Yes in Step 310 of Figure 6), multiple temperature period data (planned ambient temperature, water shutoff period) are obtained for each test condition.

[0045] Figure 7 is a flowchart showing the main processes performed by the water stop life estimation program of the present invention. As shown in this figure, the water stop life estimation program of the present invention receives multiple input temperature period data (Step 401 in Figure 7). At this time, multiple temperature period data related to the same test conditions are used as a dataset, and subsequent processing is performed for each dataset.

[0046] Upon receiving multiple temperature period data, these temperature period data are scattered (plotted) on a plane coordinate system (hereinafter referred to as the "temperature period coordinate system") with the planned ambient temperature as the first axis and the water stoppage period as the second axis. Note that the planned ambient temperature can be used directly as the first axis, or, when using the Arrhenius equation, the reciprocal of the absolute temperature of the planned ambient temperature can be used as the first axis. Once the temperature period data is plotted on the temperature period coordinate system, a regression equation (hereinafter referred to as the "water stoppage lifetime estimation equation") is set based on the test data (Step 402 in Figure 7). This water stoppage lifetime estimation equation should be set as a function where ambient temperature is the explanatory variable and the water stoppage period is the dependent variable. This water stoppage lifetime estimation equation can be set as a conventionally used linear regression equation or curved regression equation, or as the Arrhenius equation.

[0047] When tests are conducted under multiple test conditions and multiple temperature period data (datasets) are obtained for each test condition, a watertight life estimation formula can be set for each test condition. For example, Figure 8 shows the watertight life estimation formulas (Arrhenius equations) set from the test results using two types of test specimens TP, where (a) shows the watertight life estimation formula set based on a test specimen TP made of hard rubber, and (b) shows the watertight life estimation formula set based on a test specimen TP made of soft rubber.

[0048] The process up to setting the water-stopping life estimation formula (Step 402) is essentially preliminary work; the subsequent steps involve estimating the lifespan of the water-stopping material to be used. First, the water-stopping life estimation formula corresponding to the conditions under which the water-stopping material will be used is read out (Step 403 in Figure 7). Here, the conditions for using the water-stopping material include, for example, the hydrostatic pressure (environmental pressure) corresponding to the required immersion depth at the site of use, the compressibility of the water-stopping material during use, and the type of water-stopping material, which correspond to the planned water supply pressure, planned compressibility, and type of test specimen TP, respectively. When selecting and reading an appropriate water-stopping life estimation formula, the system can be configured so that the operator specifies the formula from a list of displayed formulas, or it can be configured so that the system automatically selects the water-stopping life estimation formula according to the water-stopping material usage conditions entered by the operator.

[0049] When the water-stopping life estimation formula corresponding to the usage conditions of the water-stopping material is read out, the ambient temperature entered by the operator is accepted (Step 404 in Figure 7). Then, by inputting the ambient temperature into the water-stopping life estimation formula, the water-stopping period from when the water-stopping material is installed until it can no longer stop water is calculated. The calculated water-stopping period is output by displaying it on a screen or printing it out (Step 405 in Figure 7).

[0050] 3. Method for evaluating water-stopping performance Next, the method for evaluating the water-stopping performance of the present invention will be explained in detail with reference to Figure 9. The method for evaluating the water-stopping performance of the present invention is a method for evaluating the water-stopping performance of a water-stopping material using the test apparatus 100 described above. Therefore, explanations that overlap with those described in the test apparatus 100 and the water-stopping life estimation program will be avoided, and explanations will mainly focus on the content specific to the water-stopping performance evaluation method of the present invention. In other words, content not described here is the same as that described in "1. Test Apparatus" and "2. Water-Stopping Life Estimation Program".

[0051] Figure 9 is a flowchart showing the main steps of the water-stopping performance evaluation method of the present invention. When evaluating the water-stopping performance of a water-stopping material using the test apparatus 100, first, various plans for conducting the test are formulated, such as setting the "test conditions" (Step 501 in Figure 9). Here, the test conditions include the planned compression ratio of the test specimen TP, the planned water supply pressure supplied by the pumping means 150, and the planned ambient temperature at which the test specimen TP is held by the heating means 170. Of these, the planned compression ratio of the test specimen TP can be set to a predetermined value as described above, or it can be set by performing a pumping test using the test apparatus 100 while gradually changing (increasing) the compression ratio of the test specimen TP (planned compression ratio setting step).

[0052] Once the test plan is formulated, the test specimen TP is set in the compression tester (Step 502 in Figure 9). Specifically, the spacer 130 and the test specimen TP are placed between the upper compression plate 110 and the lower compression plate 120, and the upper compression plate 110 and the lower compression plate 120 are tightened with the joining means 140 to compress the test specimen TP until it reaches the same thickness as the spacer 130. At this time, it is also possible to compress the test specimen TP to the planned thickness while measuring its thickness without placing the spacer 130.

[0053] Next, the compression tester with the test specimen TP set inside is placed in the heating means 170, adjusted to a predetermined ambient temperature, and held for a certain period of time to accelerate the thermal degradation of the test specimen TP (Step 503 in Figure 9). After a certain period of time, the water supply pipe WP is connected to the water injection hole 110H of the upper compression plate 110, and a "pressure feeding test" is performed in which water is pressurized and sent to the test specimen TP inside the compression tester by the pressure feeding means 150 (Step 504 in Figure 9). If the water-stopping performance is confirmed as a result of the pressure feeding test, the water-stopping performance of the test specimen TP is evaluated as effective. On the other hand, if the water-stopping performance is not confirmed, the test specimen TP is evaluated as not being able to stop water.

[0054] To determine the water-stopping life estimation formula, multiple test data (planned ambient temperature, water-stopping period) are acquired. Specifically, a series of steps are repeated, while changing the planned ambient temperature, to perform repeated pumping tests until the test specimen TP is evaluated as unable to stop water, and record the water-stopping period at the planned ambient temperature (Step 505 in Figure 9). Once multiple temperature period data are obtained, the water-stopping life estimation formula is set using the water-stopping life estimation program of the present invention (Step 506 in Figure 9). As a result, by inputting the ambient temperature into the water-stopping life estimation formula, the water-stopping period from the time the water-stopping material is installed until it becomes unable to stop water can be calculated. [Industrial applicability]

[0055] The test apparatus, watertight life estimation program, and watertight performance evaluation method of the present invention can be used in various locations where watertightness is required, such as the opening and closing doors of watertight rooms, the casings of electrical equipment, and the joints of water supply pipes. Considering that the present invention can provide more reliable watertightness to facilities where watertightness is required, and thereby enable the proper maintenance of social infrastructure such as these facilities, it can be said that this invention is not only industrially applicable but also has the potential to make a significant contribution to society. [Explanation of symbols]

[0056] 100 Test apparatus of the present invention 110 (Test apparatus) Upper compression plate 110H (Water injection hole of upper compression plate) 120 Lower compression plate (of the test apparatus) 120H (lower bolt hole of the test apparatus) 130 (Spacer for lower compression plate) 140 (Joining means of the test apparatus) 141 Bolts (for joining means) 142 (Nut of a joining means) 150 (Test apparatus) pumping means 160 Pressure measuring means (of the test apparatus) 170 Heating means (of the test apparatus) TP test specimen WP water pipe

Claims

1. A device capable of evaluating the water-stopping performance of a test specimen, A plate-shaped upper compression plate having water injection holes that penetrate in the thickness direction, A plate-shaped lower compression plate, A joining means for joining the upper compression plate and the lower compression plate, The system includes a pumping means for pumping water through the aforementioned water injection hole, The annular test specimen is placed between the upper and lower compression plates in a plan view, and the upper and lower compression plates are tightened by the joining means until the test specimen reaches the planned compression ratio. Then, the pumping means pumps water into the inside of the test specimen through the water injection hole, and the water-stopping performance can be evaluated by whether or not water leaks from the test specimen. A test apparatus characterized by the following features.

2. A device capable of evaluating the water-stopping performance of a test specimen, A plate-shaped upper compression plate having water injection holes that penetrate in the thickness direction, A plate-shaped lower compression plate, A joining means for joining the upper compression plate and the lower compression plate, A pumping means for pumping water through the water injection hole, The pumping means includes a pressure measuring means for measuring the pressure when pumping water, When the annular test specimen is placed between the upper and lower compression plates, and the upper and lower compression plates are tightened by the joining means until the test specimen reaches the planned compression ratio, and then the pumping means pumps water into the inside of the test specimen through the water injection hole, the water-stopping performance can be evaluated based on the pressure measured by the pressure measuring means. A test apparatus characterized by the following features.

3. Further equipped with spacers, The test specimen is fastened by the joining means after the spacer is placed between the upper compression plate and the lower compression plate. The test apparatus according to claim 1 or 2, characterized in that it is a test apparatus.

4. The heating means for housing and heating the test specimen placed between the upper compression plate and the lower compression plate is further provided. The test specimen housed in the heating means is visible from the outside. The water supply pipe, which penetrates a portion of the heating means, connects the pressure supply means, which is located outside the heating means, to the water injection hole. The test apparatus according to claim 1 or 2, characterized in that it is a test apparatus.

5. A data entry process that accepts multiple test data entries, An estimation formula setting process that sets a water stop life estimation formula using the input test data, The system includes a function to cause a computer to perform a period estimation process that outputs the period of water retention until the test specimen becomes unable to stop water, based on the input ambient temperature and the water retention life estimation formula. The aforementioned water stop life estimation formula is a regression equation based on multiple test data, wherein the ambient temperature is the explanatory variable and the water stop period is the dependent variable, The aforementioned test data is obtained by repeatedly performing a test in which water is pumped using the test apparatus described in claim 1 or claim 2 to each of the test specimens heated and held at the planned number of ambient temperatures, and includes the water shutoff period from the start of the test at the ambient temperature until it is evaluated that water shutoff is not possible. A water stop life estimation program characterized by the following:

6. A method for evaluating the water-stopping performance of a test specimen using the test apparatus described in claim 1 or claim 2, A test specimen placement step involves placing the test specimen between the upper compression plate and the lower compression plate, and tightening the upper compression plate and the lower compression plate with the joining means until the test specimen reaches the planned compression ratio. A heating and holding step is performed in which the test specimen, placed between the upper compression plate and the lower compression plate, is heated and held at a planned ambient temperature. The test includes a step of pressurizing water into the inside of the test specimen through the water injection hole using the aforementioned pressurizing means, The water-stopping performance of the test specimen at the aforementioned ambient temperature can be evaluated. A method for evaluating water-stopping performance characterized by the following:

7. The test process is repeated until the test specimen is evaluated as unable to stop water flow, and a water-stopping period confirmation step is performed to confirm the water-stopping period from the start of the test at the ambient temperature until it is evaluated as unable to stop water flow. The system further comprises: an estimation formula setting step, which involves performing the water-stopping period confirmation step on each of the test specimens heated and held at multiple different ambient temperatures to obtain multiple test data consisting of the ambient temperature and the water-stopping period, and setting a water-stopping life estimation formula using the test data; The aforementioned water stop life estimation formula is a regression equation based on multiple test data, where the ambient temperature is the explanatory variable and the water stop period is the dependent variable. The water-stopping performance evaluation method according to claim 6, characterized by the features described above.

8. The system further includes a planned compression ratio setting step in which the planned compression ratio is set using the aforementioned test apparatus, In the aforementioned planned compression ratio setting step, after tightening the test specimen, water is pumped into the inside of the test specimen at a hydrostatic pressure corresponding to the required immersion depth. The process of setting the planned compression ratio is repeated while increasing the compression ratio of the test specimen, and the compression ratio at which the water-stopping performance of the test specimen is confirmed is set as the planned compression ratio. The water-stopping performance evaluation method according to claim 6, characterized by the features described above.

Images